'THE GENIUS OF Renaissance Italy was not all spent in art and literature. Quite as much went into politics, never more so than among the heavyweight politicians of Medicean Florence,' writes Lauro Martines, former Professor of European History at the University of California, in his superb account of the Pazzi plot of April 1478 to overthrow the ruling family of that city, the Medici.

Martines describes the initial friendship of the two families and their domination of banking and commerce in the Florentine republic. Commercial success in fifteenth-century Florence required political clout, not only within the city-state but also through the support of strong allies outside. Cosimo the Elder's brilliant foresight and diplomacy ensured